Many electrical and electronic applications utilize a removable plug insertable into a receptacle for making a detachable connection. A commonplace example of such a plug/receptacle pairing is the well-known 110 V. service receptacle and mating plug found in most homes. One such exemplar is equivalent to a National Electrical Manufacturers Association (NEMA) 5-15R or 5-15P configuration, and includes a plurality of electrically conductive blades or pins for transmitting electrical power. Similar connectors may be multiple-connector plugs designed for transmitting electrical or electronic signals. By way of illustration, but not limitation, the male portion of such plugs may take the form of blades, pins or prongs, or the like. All such male elements will hereafter by referred to, for clarity, as "blades". It will be obvious to those of ordinary skill in the art that this term comprehends any and all such insertable, or male, plug elements.
In many applications the friction fit provided between the receptacle and the jack, or plug, is completely adequate for its intended purpose. Such an example might include the well-known lamp, or other light-duty electrical appliance. Other electrical connections, however, are more critical and require at once a greater resistance to inadvertent plug withdrawal, and an increased security of electrical contact. Examples of some of these applications include critical alternating current power connections, such as computer power supply connections, audio or audio-visual power supply plugs, and speaker cables. An example of the latter is New Monster Cable.RTM. available from Monster Cable.RTM., 274 Wattis Way, South San Francisco, Calif. 94080.
U.S. Pat. No. 4,384,758 teaches an expandable electrical connector of the "banana" type which is expandable by a user within a socket or receptacle. The design taught therein is adequate for single connector plugs, but provides no suggestion as to a methodology for effecting a similar secure connection on multiple connector plugs. What is needed in such plugs is a means for simultaneously engaging and expanding at least one, and preferably a plurality of, the blades of the plug while retaining an electrical separation therebetween.
What is needed then, is a methodology for retaining such electrical, or electronic plugs, especially multiple-connector plugs, tightly engaged in their respective receptacles, while rendering them easily removed when such removal is required. To affect this desirable plug security feature in the electrical trades, for instance for retaining a 110 V. plug in its receptacle, an electrician currently utilizes a screw or screw attachment to and/or through the grounded receptacle plate covering the receptacle. In some electronic applications, there is provided a separate element which attaches to the electric or electronic chassis, chassis receptacle and physically covers the plug. This is most commonly found in situations where the male element is mounted on the chassis and holds a female plug, i.e. an IEC removable power cord. This chassis-attached element does not form part of the IEC power cord assembly itself.
Neither the previously discussed practice of screwing a plug into a receptacle wall plate, or the IEC power cord locking element guarantees a good electrical connection at the electrical contacts.
What is then further needed is a methodology whereby an electrical or electronic multiple connector plug is maintained tightly engaged in its receptacle, retaining to the user the ability to easily remove the plug when such removal is required, while simultaneously improving the electrical contact between the plug elements and receptacle elements as a result of the engagement therebetween, and maintaining the electrical separation of the several plug elements.